Impregnating device and process



Aug. 4, 1959 M. o. SCHUR IMPREGNATING DEVICE AND PROCESS Filed Jan. 26, 1956 Mrm-wrwe M1704 dim m? United States IMPREGNATIN G DEVICE AND PROCESS Milton 0. Schnr, Asheville, N.C., assignor, by mesne assignments, to Olin Mathieson Chemical Corporation, a corporation of Virginia Application January 26, 1956, Serial No. 561,541 6 Claims. (Cl. 118-38) This invention relates generally to an apparatus and process for impregnating a continuous web with liquid and more particularly to a device and process for infusing liquid into a continuous web of paper or other absorbent material.

Paper and similar materials are ordinarily impregnated with a liquid such as oil, wax, fats and the like by means of a spray or by a coating roll which dips into a pan of the liquid and transfers the liquid from the pan to the paper web as it is passed over the roll. The excess liquid is usually removed from the web by passing it between rolls or against a scraper. Another proposed method of impregnating paper is to dip it in a liquid and thereafter remove the excess by squeegee rolls or similar means. Such processes are sometimes dilficult to control and as a result the product is not uniformly impregnated with the liquid especially if the sheet is to be impregnated with less than enough liquid to fill substantially all its voids, or when the impregnating liquid is high in viscosity in comparison with, say, the viscosity of water.

It is, therefore, an object of this invention to provide an improved apparatus and process for impregnating a continuous web with a liquid. Another object of the invention is to provide an apparatus and process for uniformly impregnating a web with a liquid. A further object of the invention is to provide an apparatus and process for producing a web of paper, fabric or similar material with a fusible material in predetermined quantities. A still further object of the invention is to provide a novel apparatus and process for producing a plurality of webs in a single operation with an impregnate substantially uniformly infused throughout each of the webs. Still another object of the invention is to provide an apparatus and process adapted for producing in one operation from a single web a plurality of webs each substantially uniformly impregnated with a liquid but each containing a quantity of impregnate per unit area independent of the quantity in the other web.

Other objects will become apparent from the following description taken with reference to the accompanying drawing in which Figure 1 is a perspective view of an embodiment of the apparatus provided by this invention; and,

Figure 2 is a longitudinal sectional view through an embodiment of the container utilized for applying the liquid to the web.

Generally speaking, the foregoing objects are achieved in accordance with this invention by providing a slotted but otherwise closed container for a liquid connected to a supply of the liquid through a suitable means for delivering metered amounts of the liquid to the container at a rate synchronized with the linear speed of the web which is passed over the container and in contact with the slot. The container is preferably an elongated tube having a slotted upper surface and is tapped and provided with a conduit means such as a pipe or tube connected to a suitable positive displacement pump or other means for delivering a liquid to the container. The speed f t. i a 3.

of the pump is determined by means of a variable speed drive and the speed of the means which moves the web over the slotted container.

An apparatus particularly well suited for producing a plurality of webs from a single web of greater width, each web substantially uniformly impregnated with a liquid in accurately controlled quantities, has a container provided with a plurality of slots each slot being slightly less in length than the width of the web desired. This container is divided into compartments with each compartment having one slot. Each compartment is also provided with a separate means for delivering liquid thereto independent of the means used for another compartment. A continuous web of greater width than that desired in the finished product is passed over the slotted surface and into contact with each slot and after impregnation is slit into a plurality of webs of the desired width by means of suitable slitter knives.

Referring now to the drawings, an elongated tubular container 1 having a plurality of slots 2 each about & inch in width and about 1 5 inches in length is shown with a paper web 20 stretched across the surface of the container and in contact with the slots 2. Container 1 is shown in more detail in Figure 2 and may be conveniently made from a section of iron pipe having the desired number of slots therein. The container is divided into compartments 3 by means of synthetic rubber gaskets 6, for example neoprene gaskets, each supported by two metal washers 5 and 5 earned by rod 4. Tubular spacers 7 fit loosely over rod 4 and between washer 5 and washer 5. The tubular spacers 7, the washers 5 and 5 and gaskets 6 are of dimensions such that when nuts 8 are tightened 0n the threaded portion 9 of rod 4, the distance from the center of one gasket 6 to the center of the next gasket 6 is equal in every case and is the same as the distance between the slots 2 in pipe 1. The diameter of gaskets 6 is such that they slide easily through container 1 before nuts 8 are tightened but after the nuts are tightened and the gaskets have been compressed between washers 5 and 5 and therefore have been expanded in diameter, the gaskets 6 fit snugly against the inside of con tainer 1 and form leakproof partitions.

Returning now to Figure 1, container 1 is fitted with tapped holes 10 through which the fluid with which the paper is to be impregnated is delivered. Each compartment has its independent inlet 10 and each has a conduit 11 extending between tapped holes 10 and positive displacement pumps 12. A pump such as manufactured by Zenith Products Company of the type ordinarily used in the manufacture of rayon is particularly well suited for the purpose. Pumps 12 are driven by gears 13 on shafts 14, which in turn, are driven by shaft 15 through the variable speed drive 16. Shaft 15 is driven by any suitable means such as an electric motor connected thereto. Pumps 12 draw liquid from supply tank 17. Tank 17 is fed from a liquid reservoir through a pump and the level in tank 17 is maintained through suitable upper and lower limits by means of a fioat operated switch.

Slitter knives 18 divide the web 20 into a plurality of webs somewhat wider than the length of slots 2. The spacing of the slitter knives correspond exactly to the spacing of gaskets 6 in container 1.

In operation the web being impregnated is driven by frictional engagement with the surface of roll 19 carried by drive shaft 15. The drive roll 19 may be mounted in any appropriate manner to permit movement of this roll away from the roll of finished paper as the paper is being wound on the latter roll. The speed of shaft 14 is adjusted by means of speed changer 16 so that the volume of impregnating liquid, such as a lanolin-oil composition, for example, fed by the pumps 12 corresponds to the quantity of liquid desired per unit area of web undergoing impregnation. Since the speed of the pump will vary with the speed of the web, the quantity of liquid delivered per unit area of web passing over the slot will be constant regardless of variations in linear speed of the Web. With such an apparatus the speed of the web can be as much as '600 feet per minute 'or more and uniform impregna tion will still be obtained. The placemeiit of' slitter knives 18 corresponds to the interruption between the slots 2 in container 1. As the web is impregnated, the area lying immediately over the 510132 darkens as the liquid is absorbed;' The space on the web which does not lie over the 'sljots'2 remains light. The, width of the light lines is about inch in thisparticular embodiment and after the paper has been slit and wound into bobbins, the liquid in the paper" spreads to the very' edges of the bobbins. Because the slots are discontinuous and no liquid is placed in the web between the slots and because the web 'is slit along the dry line lying between the bands of liquid, each of the resulting webs contains only that liquid coming from one compartment. Consequently, the impregnation of the sheet is very uniform over the entire width thereof. i I a As indicated hereinbefore it is possible to use a container having only one slot substantially equal to the width of the web being impregnatedf This is true even though the resulting impregnated web is to be cut into aplurality of webs. container having a plurality of slots when a plurality of webs are to be formed from a singleweb because greater uniformity of oil distribution within the web is obtained. The apparatus having aiplnrality of slots isparticularly well suite'dfor manufacturing a single web having a plurality oflba n ds of a material. The slitters, of course, are not used. I i

If it is desired to produce a paper which has a plurality of perforations therein, a suitable perforating roll may be placed between the web supply roll and. the rewind roll. The'web may be impregnated withtheliquid either before or after it has been perforated. a

The apparatus provided by this invention has been found particularly advantageous for impregnating paper to be used for wrapping the hair while it is being curled with chemical solutions. Such paper' is frequently impregnated with lanolin or similar mater'ialj The paper must be impregnated with closely controlled percentages of'the material within the range of about 10% to 30% by weight. Paper suitable for this purpose is very light inweiiglrthaving a basis weight inthe neighborhoodof about 16 grams per square meter. These papers arepreferably perforated so, when such papers are prepared in accordance with this invention, a perforating roll is combined with the container 1, the pumps and' slitter shown in the drawing. This paper has about 56 perforations per square inch with each perforation being about 0.4 7 by .55 millimeters. l

The apparatus and process of the invention is suitable for impregnating fabrics, regenerated cellulose, plastic films, paper'and the like with any liquid which will difiuse into the material. Molten wax, lanolin and various kinds of 'mineral oils are examples of the typesof impregnates that can be utilized.

Although the invention has been disclosed in detail in connection with the foregoingembodiments, it is to be understood that variations can be made therein by those skilled in the art without departing from the spirit and the scope of the invention except as it is limited by the appended claims.

I claim:

1. In a dispensing device a hollow member having an inner wall, a plurality of resilient gasket means slidably received in said hollow member and spaced from each other, means to releasably expand said gasket meansinto sealing engagement with the inner wallof said hollow member to define a plurality of individual compartments" adapted to contain a fluid, means to supply to each of said It is preferred, however, to use a compartments with a fluid to be dispensed therefrom, and an opening in each of said compartments through which said fluid is dispensed.

2. In a dispensing device a hollow member having an inner wall, a plurality of gasket means slidably received in said hollow member and spaced from each other, and means to expand each of said gasket means into sealing engagement with the inner wall of said hollow member to define compartment means within said hollow member.

3. In the dispensing device of claim 2, said gasket means having side walls transverse to the inner wall of said hollow member and a pair of rigid members engaging the side walls of each gasket means, said means to expand said gasket means into sealing engagement with the inner wall of said hollow member comprising means to draw the members of each pair of rigid members toward each other, thereby compressing said gasket means to expand said gasket means into sealing engagement with the inner wall. of said hollow member.

In the. dispensingdevice of claim 3, said means to draw. the members of each. pair of rigid; members toward each other comprising. spacer means. between adjacent faces of the rigid members of adjacent gasket means.

5. In a dispensing; device a hollow member having an inner, wall, a plurality of resilient gasket means in. saidhollowmemberand spaced: from each other, said gasket means having side walls transverse to, the inner wall of said hollow member, apair of rigid members. engaging the sidewalls of each gasket means, spacer meansbetween adjaeent. faces of, the rigid membersv of adjacent gasket means, said gasketv means, rigid, members, and spacer means being slidably receivedin said hollow member andv slidably. mounted on arod in said hollow member, and clamping meansonthe ends of said rod to clamp said gasketmeans, rigid members, and spacer means together to expand said gasket means into sealing engagement with the inner. wall of SZlQghQHQW member. thereby defining compartment means within .said hollow member.

6;. A me thod of uniformly impregnating.. with fluid a continuously advancing web of fibrous material in aseries of unitarea increments, said material having a given unit weight anda given absorbability, without recirculating or overflowing the fluid and, without saturating the web comprising. the steps of: providing a plurality of spaced, open receptacles for. receiving the fluid material, passing the webfover the receptacles so that the web encloses each open receptacle, continuously and .directly pumping said fluid to each of the receptacles at a given rate effective to cause said fluid to be diseharged from said receptacles at r 1 theffs'ame rate, controlling. the pumping rate accurately rate'and the spacing of said openings being effective to develop a predetermined and a substantially uniform increase in the unit weight of said fibrous material where the increase in unit rate is substantially uniform throughout each unitarea thereof, said rate of fluid supply andsaidQrateof fluid, dischargeto and from said receptacles being maintained at all times at a volume which 1s less ..than the amount of. fluid required to saturate the web.

References Cited in thefileof this patent UNI-TED STATES PATENTS 760,123 How May 17,- 1904 1,851,538 Day et al Mar. 29, 1932 2,929,127 Turner 061. 3, 1933 2,251,264 Berch et al Aug. 5, 1941 2,288,773 Beck July 7, 1942 2,289,68 Soog 1 July 14, 1942 2,302,096 Battey Nov. 17, 1942 2,464, 49 Coward Mar. 22, 1949 2,526,991 Biddle- Oct. 24, 1950 2,599,680 Weeks V V June 10, 1952 7 6 9. 9n 1 rI---.--.-.-.-. "Ap 9 1955 

